|A buckyball containing a water molecule can be steered to a target.--Courtesy of Columbia|
Using a soccer-ball-shaped nanoparticle named after famed inventor Buckminster Fuller, researchers at Columbia Engineering have created a drug-delivery capsule with precise targeting capabilities.
The "buckyball," or Buckminsterfullerene, named after Fuller for his geodesic dome design, is a hollow sphere composed of 60 carbons arranged into pentagon-shaped panels. At about one nanometer, a buckyball is relatively large (though about 6,000 to 8,000 times smaller than a red blood cell), and the researchers were able to isolate a single water molecule inside the sphere to drive it forward--essentially, the water molecule with its polar charges acts as the nonpolar sphere's steering wheel, directing it toward its target. It is the first attempt to manipulate a nonpolar molecule by an inserted polar molecule.
Thus, using an external electric field, the researchers found they had precise control over where the structure went and how long it took to get there. And because drugs tend to be polar like water molecules, they would act much the same way when directed by either an electrical or magnetic field, according to the study published in the journal Physical Review Letters.
"The important role of hydrogen bonds in the properties of water, like surface tension and viscosity, and the precise interactions between a single water molecule and hydrogen bonds, are still unclear," said lead author Xi Chen in a statement. "[S]o our new technique to isolate a single water molecule free from any hydrogen bonds provides an opportunity for answering these questions."
The researchers received funding from the National Science Foundation and the Defense Advanced Research Projects Agency.